Salt Lake Community College
Meteorology 1010 Fall 2014
AJ Allred, Adjunct
Practice Quiz 11
Notes to students: <The notes that go with this quiz are found in the version posted on Canvas, not here>. See
also the announcement for this quiz in Canvas.
1. Why is very humid air near the surface necessary for severe thunderstorms?
a. High humidity strengthens a cold front.
b. High humidity makes air denser.
c. High humidity makes rising air cool more rapidly.
d. Lapse rates are higher in humid air.
e. More latent heat is available as energy for the storm.
2. What is the maximum possible time that a hurricane might be overhead at any location, based on the
following information: maximum wind speeds at 125 mph, humidity above 70%, a pressure gradient
of 100mb, and steady storm movement over the ground at 10mph? The diameter of the hurricane is
200 miles.
a. 24 hours
b. 30 hours
c. 20 hours
d. 40 hours
e. There is not enough information provided to estimate how long the storm might be overhead
3. What is entrainment?
a. Cool, dry air feeding into a thunderstorm updraft.
b. Cool, humid air feeding into a thunderstorm updraft.
c. Cool, dry air being pulled into a thunderstorm by downdrafts.
d. Warm, humid air being pulled into a thunderstorm downdraft.
e. Bumpy turbulence caused by rapidly rising air that often includes lightning and hail.
4. An air mass thunderstorm almost rarely lives long enough to create very severe weather because
___________:
a. downdrafts quickly become strong enough to shut off influx of moisture rising into the storm
b. atmospheric instability dissipates quickly as heat and humidity diminish with altitude
c. in places like Utah, there is often not enough humidity to maintain a long-lasting storm
d. in the tropics, there is fairly uniform warmth and humidity, with no mass of drier, cooler air to provoke
more vigorous, prolonged lifting
e. All of the above are factors that help limit the duration of simple air-mass thunderstorms around the
world
5. Which of the following is not true of thunderstorms?
a. Over-shooting clouds may reach the mesopause during the mature stage.
b.
c.
d.
e.
Updrafts dominate in the cumulus stage.
Severe updrafts weaken during the entrainment downdraft stage.
Downdrafts dominate in the dissipating stage.
Downdrafts and updrafts are found side by side in the mature stage.
6. In spite of low cost, floating data buoys and balloons are no longer as important for locating and
tracking severe storms. Cloud cover is part of the phenomena that satellites observe. Remote sensing
by satellites is hugely important in countless ways, including data about humidity, wind speed and
direction, cloud tops, reflectivity, precipitation, and sea level variation.
True ____
False ____
7. If you see lightning and then hear the associated thunder 20 seconds later, the lightning flash was
about ________ mile(s) away.
a. three
b. four
c. one
d. five
e. two
8. What causes the dissipating stage of a thunderstorm?
a. Converging surface winds.
b. Loss of radiant energy from cloud tops.
c. Release of latent heat within the cloud.
d. Converging winds aloft.
e. Spreading downdrafts that cut off air inflow for feeding the storm.
Note to Question 8 below:
1. The term ‘landfall’ means the location where a storm crosses from ocean to land
2. “mb gradient” means the air pressure difference or gradient from outside the storm to the lowest
pressure center inside the storm.
3. In class we discussed that a ‘spring tide’ occurs twice month, rather than just in the Spring. Are
spring tides weaker or stronger than normal daily tides? What difference could it make?
9. What combination should produce the greatest storm surge?
a. Winter tide, 300mb gradient, landfall at 4°N.
b. Late summer tide with 100mb gradient, landfall at 48°N.
b. Spring tide, 100mb gradient, landfall at 20°N.
c. Autumn tide, 600mb gradient, landfall at 60°N.
e. High tide, 250mb gradient, landfall at 20°N.
10. In recent years, people in the path of a tornado can expect to get at least 10 minutes of warning.
Which of the following statements is also true?
a. Using modern social media, we can and should warn everyone in the entire region
b. Meteorologists have no way of projecting pathways of unpredictable tornadoes, so warnings should be
equally distributed and fair for everyone in the region.
c. Based on experience, warnings are most important for people located northeast of the funnel cloud.
d. Warnings should be issued to people located south, north, east and west of the funnel cloud
e. Precautionary evacuation is always appropriate whenever a funnel cloud might appear.
11. The outflow at the top of a hurricane prolongs the storm's lifespan because it _____:
a. prevents rising air from diverging at the top of the storm
b.
c.
d.
e.
causes winds to converge at the top of the storm.
prevents rising air from “piling up” at the top of the storm
prevents surface divergence from "filling in" the low-pressure center of the storm.
brings in cold air to strengthen the hurricane through its eye.
12. A tropical depression occurs when falling air pressure leads to lower sea level for up to several hours
before the storm begins to dissipate.
True ____
False ____
13. Inundation or flooding by storm surge is caused by ____________.
a. high wind speeds
b. heavy precipitation
c. high air pressure
d. high ocean waves
e. high latent heat.
14. To reach hurricane status ________________.
a. ground track speed of the whole hurricane must increase to at least 70 mph
b. ground track speed of the hurricane must reach at least 15-20 mph
c. sustained winds must reach at least 74 mph
d. maximum brief wind gust speeds must reach at least 74 mph
e. All of the above are required for a Saffir-Simpson hurricane status declaration.
15. Signals received by Doppler radar will pulse more quickly when reflected back from ________.
a. dry air moving toward the receiver antennae
b. humid air moving away from the receiver
c. humid air rising quickly toward the receiver
d. precipitation that is blowing toward the receiver
e. precipitation that is blowing away from the receiver